Urgency seen in right whale research
With southern U.S. waters yielding no North Atlantic right whale calves this year, scientists have turned to Northeast seas — the next stop on the critically endangered whale’s migratory path — for insight.
“We can say with a fair amount of certainty that there were zero calves,” said science consultant Caroline Good, a member of the federal Atlantic Large Whale Take Reduction Team. “It’s a very serious situation.”
Federal scientists with the Northeast Fisheries Science Center in Woods Hole have announced their plan for more research boat trips in Cape Cod Bay because of larger numbers of right whales arriving earlier than usual to feed. The Center for Coastal Studies has begun raising $100,000 in donations to expand its airplane surveys north, from Provincetown to Cape Ann, to explore new areas where the whales may be congregating.
In what has for at least three decades been a predictable annual migratory pattern, right whales have calved and nursed in warm waters off Georgia and Florida and then traveled in winter and early spring to feeding areas such as Cape Cod Bay, and eventually reaching feeding areas off Canada by the summer.
The whales are believed to follow particular forms of zooplankton in the ocean, and now those migratory patterns are in flux.
“They have largely abandoned the Bay of Fundy feeding grounds,” said marine mammal researcher Lisa Conger, with the science center in Woods Hole. Right whales are now showing up in larger numbers farther north, in the Gulf of St. Lawrence, by late June and early July, she said.
The science center researchers also intend to take more tissue samples from whales in Cape Cod Bay, which allows scientists to track mother and calf survival rates and monitor the overall population.
Last year, with 12 documented right whale deaths in the Gulf of St. Lawrence, and at least four off Cape Cod, and only five documented births, the survival of the remaining 450 animals is considered a top priority. The deaths are primarily from ship strikes and entanglement in fishing gear.
Many researchers at the science center’s large whale research program have a “laser-like” focus on North Atlantic right whales, said zoologist Peter Corkeron, who heads the program. That research program is primarily based on aerial and vessel surveys in the Northeast including Canada, in cooperation with colleagues working on underwater acoustic recordings and researchers outside of the science center.
The boat and airplane surveys provide information to state and federal officials and researchers about where whales are congregated, which whales are in the area, where boats and fishing gear are located, and densities of zooplankton, which the whales consume. That type of information is then used to help inform management decisions for the species, said Center for Coastal Studies right whale ecology program director Charles “Stormy” Mayo.
Given that high percentages of the North Atlantic right whales continue to return to Cape Cod Bay, Mayo hopes to expand his program’s air and boat surveying techniques northward to determine where the right whales gather prior to entering the bay, and to document zooplankton concentrations there, Mayo said. “We just don’t know where they are,” he said.
“We do have a commitment from (the National Oceanic and Atmospheric Administration) to at least continue our very important annual program in Cape Cod Bay for next year but they are struggling with cuts in their federal budgets,” said Richard Delaney, head of the Center for Coastal Studies, referring to the existing airplane and boat surveys.
From a high of $11.8 million in fiscal year 2005, the National Marine Fisheries Service has funded the endangered North Atlantic right whales conservation program at more than $8 million annually since fiscal year 2009, according to agency spokeswoman Katherine Brogan.
The declaration of an unusual mortality event for right whales last year by the National Marine Fisheries Service added another $128,000, Brogan said.
In late March, Canadian government officials announced new restrictions on snow crab fishing, along with new restrictions on ship speeds and $1 million more each year to free marine mammals from fishing gear to protect North Atlantic right whales.
But boosting the right whale calving rate is, possibly, an even harder task given the many unknowns about how whales find food, Good said.
Calving rates can vary dramatically — such as a high of 39 in 2009 to a low of 5 last year, according to the North Atlantic Right Whale Consortium. And there may be links between calving rates and the availability and location of food the right whales want, the densities of food and the effects of climate change on water temperature, currents and deep-water physical processes.
“There is clearly a problem with the whales being able to find sufficient food in order to reproduce,” Good said. “If the females don’t bulk up over the winter, they won’t be able to support lactation.”
Typically, female right whales become sexually mature at around 10 years old, and they give birth to a single calf after a yearlong pregnancy. The calves then nurse for one to two years.
“They are trying to nurse for many months during which time they are fasting,” Good said. “The only way to do that is to build up a tremendous amount of fat. They don’t have that now.”
There are many contributing factors to the lack of calving, such as adult females being killed, or having their energy depleted from carrying fishing gear, Good said. “But a total cessation strongly suggests food limitation,” she said. The whales may be looking for high densities of their food, and for now not finding it, she said.
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